CotD: ‘Thomas’ and Tweetie first appeared together in 1947’s “Tweetie Pie”. Big question: Is Tweetie male or female?
Tweetie Pie (1947) — Merrie Melodies Theatrical Cartoon Series
Thomas the cat (to be known in later cartoons as Sylvester) finds Tweety in the snow warming himself by a cigar butt. Thomas’s mistress rescues the little yellow bird before her cat can devour him, but Thomas doesn’t give up. He uses stacks of chairs and a Rube Goldberg setup to get at Tweety while trying not to get caught by the lady.